Electronic Device and Recording Medium

ABSTRACT

An electronic device comprises a display unit, determination unit, parameter acquiring unit, and display control unit, and is configured as follows: the display unit can provide a three-dimensional display that makes an image stereoscopically viewable; the determination unit determines a posture of the display unit; the parameter acquiring unit acquires a control parameter that is related to the posture and intended to control a display operation of the display unit; the display control unit controls, on the basis of the control parameter acquired by the parameter acquiring unit, the display operation of the display unit, which is associated with the three-dimensional display.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.12/692,313 which was filed with the U.S. Patent and Trademark Office onJan. 22, 2010. This application claims the benefit of Japanese PatentApplication No. 2009-015787, filed on Jan. 27, 2009, the entiredisclosure of which is incorporated by reference herein.

FIELD

This application relates generally to an electronic device and arecording medium, and more particularly, to an electronic device usedpreferably for stereoscopic image display, and a recording medium.

BACKGROUND

Mobile communication terminals, such as a cellular phone, have beenexperiencing improvement into the ever-higher performance of additionalfunctions involving image display, such as a camera function and a TVbroadcast receiving function. This advancement is accompanied byemergence of diversified structures of the display device. Although manyconventional mobile communication terminals are equipped with avertically long screen, a screen of horizontally long shape is suitablefor use as a TV screen. Therefore, common mobile communication terminalcome to provide a display device that can display images on a screenturned into a position where the screen is horizontally long.

In such mobile communication terminals, a display direction of an imageis changed by detecting the horizontally long state of the casingitself. Besides, among mobile communication terminals having a foldablecasing, one in which, by configuring that only a part corresponding to adisplay device can be rotated, only the display device can be directedin a vertically long direction or a horizontally long directiondepending on the intended use is also used in practice. Thus, displaycontrol, depending on a plurality of screen directions, is performed.

Regarding a display device used for such a mobile communicationterminal, one using a liquid crystal display panel is mainstream, and astereoscopic image display technique using a liquid crystal displaytechnique has also been established (for example, Japanese Patent No.2857429).

Also, in such a stereoscopic image display technique, there is also atechnique that can easily provide a three-dimensional image displaywithout discomfort on the basis of a two-dimensional image (for example,Unexamined Japanese Patent Application KOKAI Publication No.2004-320189).

By using the techniques as described above, a stereoscopic image displaycan be easily provided even in a small electronic device such as amobile communication terminal. However, a stereoscopic image has thedisadvantage of being difficult to visually recognize displays unlessthe display control that meets conditions upon viewing (e.g., visualdistance and angle, distance between viewer's eyes, and the like) isperformed. As described above, in any mobile communication terminal, avariety of configurations are available for a display device. Therefore,a user is unable to appropriately visually recognize a stereoscopicimage when a posture of the device is changed, problematically.

SUMMARY

The present invention is made in consideration of the above situations,and provides an electronic device that can achieve a stereoscopic imagedisplay having high visibility, and a recording medium.

An electronic device according to the first aspect of the presentinvention comprises: a display unit that can provide a three-dimensionaldisplay making an image stereoscopically viewable;

a determination unit that determines a posture of the display unit; anda display control unit that, on a basis of the posture determined by thedetermination unit, controls a display operation of the display unit,the display operation being associated with the three-dimensionaldisplay.

A recording medium according to the second aspect of the presentinvention records a program that instructs a computer to function as:

a display unit that can provide a three-dimensional display making animage stereoscopically viewable;a determination unit that determines a posture of the display unit; anda display control unit that, on a basis of the posture determined by thedetermination unit, controls a display operation of the display unit,the display operation being associated with the three-dimensionaldisplay.

Effect of the Invention

According to the present invention, the visibility of a stereoscopicimage display can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of this application can be obtained whenthe following detailed description is considered in conjunction with thefollowing drawings, in which:

FIG. 1A is a diagram illustrating an example of a straight type mobilecommunication terminal according to the first embodiment of the presentinvention;

FIG. 1B is a diagram illustrating an example of a slide type mobilecommunication terminal according to the first embodiment of the presentinvention;

FIG. 1C is a diagram illustrating the example of the slide type mobilecommunication terminal according to the first embodiment of the presentinvention;

FIG. 2A is a diagram illustrating a relationship between a posture(direction) of a casing and a screen direction in a straight type mobilecommunication terminal illustrated in FIG. 1A;

FIG. 2B is a diagram illustrating a relationship between a posture(direction) of a casing and a screen direction in a slide type mobilecommunication terminal in the state illustrated in FIG. 1B;

FIG. 2C is a diagram illustrating a relationship between the posture(direction) of the casing and the screen direction in the slide typemobile communication terminal in the state illustrated in FIG. 1C;

FIG. 3 is a block diagram illustrating an internal configuration of themobile communication terminal according to the first embodiment of thepresent invention;

FIG. 4A is a diagram schematically illustrating a configuration of adisplay unit;

FIG. 4B is a diagram illustrating an example of an image for left eye,displayed on the display unit;

FIG. 4C is a diagram illustrating an example of an image for right eye,displayed on the display unit;

FIG. 4D is a diagram illustrating an example of a pixel array of a 3Dimage;

FIG. 5A is a diagram illustrating an example of a barrier pattern on aparallax barrier panel illustrated in FIG. 4A;

FIG. 5B is a diagram schematically illustrating an image transmissionmechanism based on the barrier pattern;

FIG. 6 is a diagram illustrating an example of a “parameter table”stored in the storage unit illustrated in FIG. 3;

FIG. 7 is a diagram illustrating an example of a functionalconfiguration achieved by a control unit illustrated in FIG. 3;

FIG. 8 is a diagram illustrating an example of an “operation settingtable” stored in the storage unit illustrated in FIG. 3;

FIG. 9 is a flowchart for describing “display control processing”according to the embodiment of the present invention;

FIG. 10 is a flowchart for describing “3D display processing” performedin the “display control processing” illustrated in FIG. 9;

FIG. 11 is a flowchart for describing “2D display processing” performedin the “display control processing” illustrated in FIG. 9;

FIGS. 12A and 12B are diagrams illustrating an example of a swing typemobile communication terminal according to the second embodiment of thepresent invention;

FIGS. 12C to 12E are diagrams illustrating an example of a swing typemobile communication terminal according to the second embodiment of thepresent invention;

FIGS. 13A to 13C are diagrams illustrating an example of a mobilecommunication terminal that can be opened/closed in differentdirections, according to the second embodiment of the present invention;

FIG. 14 is a block diagram illustrating an internal configuration of themobile communication terminal according to the second embodiment of thepresent invention;

FIG. 15 is a diagram illustrating an example of a functionalconfiguration achieved by the control unit illustrated in FIG. 14;

FIGS. 16 and 17 are diagrams illustrating other examples of the“parameter table” illustrated in FIG. 6; and

FIG. 18 is a block diagram illustrating another internal configurationof the mobile communication terminal according to the first or secondembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments according to the present invention will hereinafter bedescribed with reference to the drawings.

First Embodiment

In the present embodiment, there is described a case where an electronicdevice according to the present invention is included as, for example, amobile communication terminal such as a cellular phone. In the presentembodiment, a mobile communication terminal as illustrated in FIG. 1 isenvisaged.

In FIGS. 1A to 1C, FIG. 1A illustrates an example of a so-called“straight type” mobile communication terminal 1A, and FIGS. 1B and 1Cillustrate an example of a so-called “slide type” mobile communicationterminal 1B.

The mobile communication terminal 1A has, as illustrated in FIG. 1A, forexample, operation buttons and a display unit 160 on a casing 11 held bya user.

Also, the mobile communication terminal 1B includes, as illustrated inFIGS. 1B and 1C, a casing 11 held by a user, and a casing 12 that slidesparallel to the casing 11, and has a display unit 160 on the casing 12.

In both of the mobile communication terminals 1A and 1B, a screendirection of the display unit 160 is linked to a direction (posture) ofthe casing 11 held by a user. For example, in the case of the straighttype mobile communication terminal 1A, as illustrated in FIG. 2A, whenthe casing 11 itself is vertical, a screen of the display unit 160 isbrought into a vertically long state, whereas when the casing 11 itselfis horizontal, the screen of the display unit 160 is brought into ahorizontally long state.

FIG. 2B illustrates a relationship between the posture of the casing 11and the screen direction in the slide type mobile communication terminal1B in a state illustrated in FIG. 1B, and FIG. 2C a relationship betweenthe posture of the casing 11 and the screen direction in the slide typemobile communication terminal 1B in a state illustrated in FIG. 1C.Similar to the case of the mobile communication terminal 1A, when thecasing 11 itself is vertical, a screen of the display unit 160 isbrought into a vertically long state, whereas when the casing 11 itselfis horizontal, the screen of the display unit 160 is brought into ahorizontally long state.

In the following, in the present invention, in each of FIGS. 2A to 2C, adirection of the mobile communication terminal 1A or 1B illustrated onthe left-hand sides of both arrows is defined as a “vertical direction”,and a corresponding screen direction of the display unit 160 as a“vertically long direction”. Similarly, in each of FIGS. 2A to 2C, adirection of the mobile communication terminal 1A or 1B illustrated onthe right-hand sides of the both arrows is defined as a “horizontaldirection”, and a corresponding screen direction of the display unit 160as a “horizontally long direction”.

An internal configuration of the mobile communication terminal 1A or 1B(collectively referred to as a “mobile communication terminal 1”) havingsuch a casing structure is described with reference to FIG. 3. FIG. 3 isa block diagram illustrating the internal configuration of the mobilecommunication terminal 1.

As illustrated in the diagram, the mobile communication terminal 1comprises a control unit 110, communication unit 120, voice processingunit 130, storage unit 140, operation unit 150, display unit 160, andgravitational direction detecting unit 170.

The control unit 110 includes, for example, a CPU (Central ProcessingUnit), and a RAM (Random Access Memory) serving as a work area, and itexecutes a predetermined operation program to thereby control therespective parts of the mobile communication terminal 1. That is, therespective components of the mobile communication terminal 1 arecontrolled by the control unit 110, and information transmission betweenthe respective components is performed through the control unit 110.

The communication unit 120 is a component associated with wirelessaccess at the time when the mobile communication terminal 1 makescommunication, which includes, for example, a communication device usinga communication system such as a CDMA (Code Division Multiple Access)system or GSM (Global Systems for Mobile Communications) system, and thelike, and performs wireless transmission/reception through an antenna121 corresponding to the communication system to thereby allow wirelesscommunication with an adjacent base station.

The voice processing unit 130 includes, for example, a codec circuit forvoice data, and the like, and performs processing associated with voiceinput/output of the mobile communication terminal 1. That is, the voiceprocessing unit 130 performs a voice receiving operation that convertsdigital voice data received by the communication unit 120 into an analogvoice signal to output it from a speaker 131, and a voice transmittingoperation that converts the user's speech voice inputted from amicrophone 132 into digital voice data to transmit it to thecommunication unit 120, and the like.

The storage unit 140 includes, for example, a storage device such as aflash memory, and stores the operation program executed by the controlunit 110, and also, various pieces of data necessary to embody thepresent invention.

The operation unit 150 includes, for example, buttons, keys, or thelike, that are formed on the outer surface of the casing 11, and isoperated by the user of the mobile communication terminal 1. Theoperation unit 150 comprises an input circuit connected to therespective buttons, keys, or the like, and generates an input signalaccording to the user's operation to transmit the input signal to thecontrol unit 110.

The display unit 160 is a display output device including, for example,a liquid crystal display device, and displays and outputs an image andthe like according to the control of the control unit 110. The displayunit 160 according to the present embodiment is assumed to be a displaydevice that can provide a stereoscopic image display (hereinafterreferred to as a “3D display”). A configuration of the display unit 160capable of providing such a 3D display is described with reference toFIG. 4A.

The display unit 160 according to the present embodiment includes, asillustrated in FIG. 4A, a display panel 160A and a parallax barrierpanel 160B to thereby achieve the 3D display.

The display panel 160A includes, for example, a liquid crystal displaypanel, and displays an image.

The parallax barrier panel 160B has a similar configuration to a liquidcrystal display panel, and controls transmission of light generated dueto the image displayed on the display panel 160A. For this reason, theparallax barrier panel 160B is configured in the display unit 160 so asto be positioned between the display panel 160A and a person who viewsthe screen of the display panel 160A (the person is a user of the mobilecommunication terminal 1, or the like. Hereinafter the user is referredto as a “viewer”).

An operating principle on the basis of which the display unit 160 havingsuch a configuration provides a 3D display is described with referenceto FIGS. 4B to 4D and FIGS. 5A and 5B.

In the case of using the parallax barrier panel 160B to provide the 3Ddisplay, parallax between right and left eyes is used. For this reason,in the case where the display unit 160 provides the 3D display, imagesfor the left and right eyes as illustrated in FIGS. 4B and 4C,respectively, are prepared. The images for the left and right eyes(hereinafter referred to as “left and right images”) both indicate thesame display object, but are displaced in right and left directionsdepending on the parallax.

The display panel 160A of the display unit 160 provides a display withhorizontally alternating display positions of pixels constituting theimage for the left eye and those of pixels constituting the image forthe right eye. For example, as illustrated in FIG. 4D, an image isdisplayed on the screen, in which the pixels constituting the image forthe right eye and those constituting the image for the left eye arearrayed in odd number columns and even number columns, respectively.

In other words, each of the images for the left and right eyes isdisplayed such that the pixels thereof are arrayed in every other column(line), and lines for the images for the left eye and those for theimages for the right eye are alternated. Note that the pattern of thepixel array does not need to be on the one column basis, but, forexample, the line may be formed from a plurality of pixels. Also, apixel unit may not have an integer value.

As described, the display panel 160A displays the image (hereinafterreferred to as the “3D image”) in which the images for the left andright eyes are arrayed in stripe forms, respectively. Note that, byproviding the display so as to make the lines formed by the pixels ofthe left eye image reach the left eye of the viewer and the lines formedby the pixels of the right eye image reach the right eye of the viewer,the two images having the parallax as illustrated in FIGS. 4B and 4C arerecognized by respective corresponding one of the left and right eyes.As a result, the respective images are synthesized within the brain ofthe viewer, and visually recognized as a stereoscopic image.

In this case, the parallax barrier panel 160B performs an operation thatdisplays the respective lines in the 3D image toward eyes correspondingto the respective lines. As described above, the parallax barrier panel160B has a similar structure to a liquid crystal display panel, andtherefore by controlling voltage application to an electrodecorresponding to each of the pixels, the light generated due to theimage display on the display panel 160A can be transmitted or shielded.

That is, a striped barrier pattern as illustrated in FIG. 5A is formedcorresponding to the lines of the 3D image displayed on the displaypanel 160A. Then, as illustrated in FIG. 5B, the right and left imagesdisplayed on the display panel 160A are respectively transmitted throughtransmission columns of the barrier pattern formed on the parallaxbarrier panel 160B to reach the right and left eyes of the viewer.

To achieve this, transmission/non-transmission (light shielding) shouldbe appropriately controlled for each of the stripes (lines, columns). Inthis case, it is only necessary to change the orientation of thedirection of liquid crystal molecules by controlling the voltage appliedto each of the stripes (lines, columns). This display control is changeddepending on the distance from the viewer's eyes to the display unit 160(hereinafter referred to as a “visual distance”) and the intervalbetween the right and left eyes of the viewer (hereinafter referred toas an “distance between eyes”).

Accordingly, the present embodiment is adapted to appropriately visuallyrecognize the 3D display by preparing a plurality of “conditionalparameters” in which conditions (conditions upon viewing) varyingdepending on a viewer and viewing environment, such as the visualdistance and the distance between eyes, are parameterized. The“conditional parameters” are stored in the storage unit 140. Also, inthe present embodiment, for the respectively prepared conditionalparameters, “control parameters” for forming an appropriate barrierpattern are set, and stored in relation to the conditional parametersstored in the storage unit 140. In the present embodiment, a “parametertable” as illustrated in FIG. 6 is assumed to be stored in the storageunit 140.

As illustrated, in the parameter table, for each of the screendirections of the display unit 160 (vertical or horizontal direction),the conditional parameters and the control parameters are related toeach other. In this table, a plurality of combinations of the distancebetween eyes and the visual distance are set. Also, for each of thecombinations, the control parameters for providing an appropriate 3Ddisplay are recorded. The control parameters are, for example, controlvalues of the display panel 160A, which are set to appropriately displaya 3D image depending on the screen direction, and control values (e.g.,applied voltage, number of pixels included in a line, and the like) foreach of the lines of the parallax barrier panel 160B, which areappropriate when the display is provided.

That is, in the case of displaying the 3D image as illustrated in FIG.4D on the display panel 160A, and using the barrier pattern formed onthe parallax barrier panel 160B to provide a 3D display, the 3D image isvisually recognized as the 3D display under specific conditions, andtherefore if the conditional parameters such as the visual distance andthe distance between eyes are varied, the array of the left and rightimages in the 3D image should be changed. If the array of the left andright images is changed, the barrier pattern should be changed to abarrier pattern suited to the change. For this reason, for each of thecombinations of the conditional parameters set for each of the screendirections, the control values of the display panel 160A for achievingan optimum array of the left and right images, and the control values ofthe parallax barrier panel 160B for forming a barrier pattern that isoptimum in this case, are set as the control parameters.

Note that the control parameters of the display panel 160A are assumedto be set with respect to a period and order of the pixel array of theright and left images, depending on the resolution of the display panel160A. Accordingly, the control parameters of the display panel 160A areset within a controllable resolution range, and therefore discrete tosome extent. Also, if the pixel pitch between vertical pixels isdifferent from the pixel pitch between horizontal pixels, or if thepixel aspect ratio between vertical and horizontal dimensions of eachpixel is different, the control parameters of the display panel 160Atake different control values depending on the screen direction.

Note that the distance between eyes in the conditional parameters has afixed value for the same viewer, and therefore by setting defaultvalues, efficient processing can be performed. For example, if aninitial screen display in the mobile communication terminal 1 isprovided as a 3D display, the combination of general distance betweeneyes and visual distance is specified as a default value, but insubsequent displays, the parameters used for the previous 3D display arespecified as default values. For this purpose, as indicated by hatchingin FIG. 6, the parameter table is preliminarily prepared to be able toidentify the default values.

Note that, in the example of FIG. 6, the visual distance and thedistance between eyes are set as elements of the conditional parameters;however, an angle (viewing angle) between the viewer and the screen maybe added to the elements.

Also, as illustrated in FIG. 6, each of the parameters is related to thescreen direction of the display unit 160. That is, each of theparameters is set depending on the vertically long direction (verticaldirection) or horizontally long direction (horizontal direction) asexemplified in FIGS. 2A to 2C. The direction of the mobile communicationterminal 1, i.e., whether the screen direction of the display unit 160is vertical or horizontal is determined by a detecting operation of thegravitational direction detecting unit 170 illustrated in FIG. 3.

The gravitational direction detecting unit 170 includes, for example, anacceleration sensor, which detects a gravitational direction acting onthe mobile communication terminal 1, and outputs a signal resulting fromthe detection to input it to the control unit 110.

The above describes major configurations in the mobile communicationterminal 1 according to the present embodiment, which are configurationsnecessary for the operation of the present invention, and the otherconfigurations necessary to achieve main functions and additionalfunctions of the mobile communication terminal 1 are assumed to beappropriately provided.

Operation of the mobile communication terminal 1 having theconfiguration as above is described. Note that the mobile communicationterminal 1 according to the present invention is assumed to provide animage display depending on the screen direction by performing thedisplay control of the display unit 160 in each of the cases where theposture (direction) of the mobile communication terminal 1 is verticaland horizontal as exemplified in FIGS. 2A to 2C. In this case, thedisplay unit 160 according to the present embodiment is one capable ofproviding a 3D display, and therefore when an image display iscontrolled depending on the screen direction, controls the parallaxbarrier panel 160B such that the 3D display is appropriately visuallyrecognized.

To perform such an operation, the control unit 110 executes theoperation program stored in the storage unit 140, and thereby functionsas illustrated in FIG. 7 are achieved. As illustrated in the diagram,the control unit 110 functions as an operation mode processing unit 111,image acquiring unit 112, screen direction determination unit 113, anddisplay control unit 114.

The operation mode processing unit 111 designates an operation mode ofthe mobile communication terminal 1 in accord with a signal input by theoperation unit 150 being operated by a user of the mobile communicationterminal 1. Besides, the operation mode processing unit 111 issues aninstruction to each of the functions that accords with the designatedoperation mode.

The image acquiring unit 112 acquires image data, attribute informationon the image data and the like, at the time when the display unit 160 ofthe mobile communication terminal 1 provides a screen display. In thepresent embodiment, image data on an image created for 3D display, imagedata used for normal display (hereinafter referred to as “2D display”),or the like is acquired. Also, information indicating the attribute ofthe image data, i.e., whether the acquired data is data for the 3Ddisplay or 2D display, or the like, is acquired. These pieces of imagedata are assumed to be stored in, for example, the storage unit 140, andthe image acquiring unit 112 appropriately acquires image data or thelike necessary for screen display from the storage unit 140.

The screen direction determination unit 113 determines the screendisplay direction of the display unit 160 on the basis of the inputsignal from the gravitational direction detecting unit 170. In thepresent embodiment, as illustrated in FIGS. 2A to 2C, the posture(direction) of the mobile communication terminal 1 (casing 11) and thescreen direction of the display unit 160 are linked to each other.Therefore, from a gravitational direction acting on the mobilecommunication terminal 1, which is detected by the gravitationaldirection detecting unit 170, it can be determined whether the posture(direction) of the mobile communication terminal 1 is in a vertical orhorizontal direction. The screen direction determination unit 113determines from the determined posture (direction) of the mobilecommunication terminal 1 whether the screen direction of the displayunit 160 at the time is “vertically long” or “horizontally long”.

The display control unit 114 selects parameters stored in the storageunit 140 on the basis of the operation mode specified by the operationmode processing unit 111, attribute of the image data acquired by theimage acquiring unit 112, and screen direction of the display unit 160determined by the screen direction determination unit 113. On the basisof the selected parameters, it controls the display operation of thedisplay unit 160. In this case, the display control unit 114 is assumedto perform the display control according to operation settings of thedisplay operation of the 3D display. The operation settings are assumedto be stored in the storage unit 140 as, for example, an “operationsetting table” as illustrated in FIG. 8.

In this case, as illustrated in FIG. 8, operation setting items, forexample, “Display mode”, “3D display in vertically long state”, “Displayin oblique state”, “3D display in oblique state”, and the like areassumed to be prepared. In the example of FIG. 8, regarding “Displaymode”, “3D display in vertically long state”, “Display in obliquestate”, and “3D display in oblique state”, options “3D”, “No”, “On”, and“No” are respectively set and enabled.

“Display mode” is a setting item that specifies whether or not a 3Ddisplay is provided on the display unit 160, and if the 3D display isprovided, the option “3D” is enabled, on the basis of which, the displaycontrol unit 114 controls the display unit 160 to provide the 3Ddisplay. On the other hand, if the 3D display is not provided, theoption “2D” is enabled, and on the basis of this setting, the displaycontrol unit 114 controls the display unit 160 not to provide the 3Ddisplay.

“3D display in vertically long state” is a setting item that is referredto when “Display mode” is set to “3D”, and it specifies whether or not a3D display is provided when the screen direction of the display unit 160is “vertically long”. If a 3D display is not provided when the screendirection is “vertically long”, the option “No” is enabled, whereas whena 3D display is provided even when the screen direction is “verticallylong”, the option “Yes” is enabled.

As described above, the display unit 160 according to the presentembodiment provides a 3D display using parallax between right and lefteyes, and therefore an effect of the 3D display is more likely to appearon the horizontally long screen. On the other hand, on the verticallylong screen, the effect of the 3D display may not be likely to appear.If it is better not to provide a 3D display when the screen direction is“vertically long”, “No” is specified.

“Display in oblique state” is a setting item that specifies whether ornot a screen display on the display unit 160 is provided when theposture (direction) of the mobile communication terminal 1 is oblique,i.e., the screen direction of the display unit 160 is oblique. If adisplay on the display unit 160 is not provided when the screendirection is oblique, the option “Off” is enabled, whereas if a screendisplay is provided even when the screen direction is “oblique”, theoption “On” is enabled.

Note that when the screen direction of the display unit 160 is “oblique”it corresponds to, for example, the middle of changing the posture(direction) of the mobile communication terminal 1 (casing 11) for auser of the mobile communication terminal 1 to change the screendirection from the “vertical long” state to the “horizontally long”state, or other situation. As described above, in the case where a 3Ddisplay is provided on the display unit 160, the barrier pattern isformed by the parallax barrier panel 160B; however, if the screendirection is oblique, the direction of an image being displayed on thedisplay panel 160A also becomes oblique, and therefore a barrier patternsuited to this should be made.

In this case, when the screen direction is “vertically long” or“horizontally long”, a simple stripe barrier pattern is only required;however, in the middle of changing the posture (direction) of the mobilecommunication terminal 1 (casing 11), an angle is successively changed.In this case, processing becomes complicated, and the display controlcannot follow the change in angle, so the display quality of a 3Ddisplay may be reduced. Also, it may be difficult to finely form theoblique barrier pattern itself. Accordingly, in such a case, on thebasis of the “Display in oblique state” setting, control can beperformed to make the display unit 160 stop providing a display whilethe screen direction is oblique.

“3D display in oblique state” is a setting item that is referred to when“Display in oblique state” is set to “On”. It is a setting that,although a display is provided even when the screen direction isoblique, specifies whether the display at the time is a 3D or 2Ddisplay. If when the screen direction is oblique, a 3D display is notprovided but switches to a 2D display, the option “No” is enabled,whereas if the 3D display is provided even when the screen direction isoblique, the option “Yes” is enabled. As described above, the 3D displayin the oblique state may be reduced in display quality, and therefore onthe basis of a setting of this item, the switch to a 2D display can beset while the screen direction is oblique.

Each of these setting items is set on the basis of, for example, anoperation of the operation unit 150 by a user of the mobilecommunication terminal 1, or other means.

Processing performed on the basis of the functional configurationillustrated in FIG. 7 is described. Here, the “display controlprocessing” performed when a screen display is provided in the mobilecommunication terminal 1 having a configuration as described above isdescribed with reference to a flowchart illustrated in FIG. 9. “Thedisplay control processing” is started when a display operation on thedisplay unit 160 is performed (e.g., power on of the mobilecommunication terminal 1, resuming from a sleep mode, or the like).

After the processing has been started, the screen directiondetermination unit 113 instructs the gravitational direction detectingunit 170 to perform a detecting operation. As a result of the detectionobtained by the detecting operation of the gravitational directiondetecting unit 170, it thereby determines the screen direction of thedisplay unit 160 (Step S101). That is, the screen directiondetermination unit 113 determines, on the basis of a gravitationaldirection acting on the mobile communication terminal 1, which isdetected by the gravitational direction detecting unit 170, which of the“vertically long”, “horizontally long”, or “oblique” direction is thescreen direction of the display unit 160.

After the screen direction has been determined, the screen directiondetermination unit 113 determines whether or not this is a processingstep associated with the start of a display operation (Step S102). Thatis, the screen direction determination unit 113 determines whether ornot the determination of the screen direction in Step S101 has been madeimmediately after the start of the present processing. In this case,because the determination has been made immediately after the start ofthe present processing, this is determined as a display operation starttime (Step S102: Yes). In this case, the screen direction determinationunit 113 notifies the display control unit 114 of the screen directiondetermined in Step S101.

The display control unit 114 performs display processing depending onthe screen direction notified by the screen direction determination unit113 (Step S104). That is, the display control unit 114 performsprocessing such as rotating or zooming on image data acquired by theimage acquiring unit 112, depending on the determined screen direction,to display a resultant image on the display panel 160A.

At the same time, the operation mode processing unit 111 refers to theoperation setting table stored in the storage unit 140 to determinewhether or not the 3D display mode is enabled (“Display mode” is set to“3D”) (Step S105).

If the 3D display mode is enabled (Step S105: Yes), the operation modeprocessing unit 111 further refers to the operation setting table todetermine whether or not the setting that a 3D display is not providedunder a predetermined condition is enabled (Step S106). In the case ofthe operation setting table exemplified in FIG. 8, this corresponds tothe case where any of the option “No” for the setting item “3D displayin vertically long state”, option “Off” for the setting item “Display inoblique state”, or option “No” for the setting item “3D display inoblique state” is enabled.

If there is no setting that a 3D display is not provided under apredetermined condition (Step S106: No), the operation mode processingunit 111 notifies the display control unit 114 of this. In this case,the display control unit 114 performs “3D display processing” (describedlater in detail) which provides a 3D display on the display unit 160(Step S200).

On the other hand, if the setting exists that a 3D display is notprovided under a predetermined condition (Step S106: Yes), the operationmode processing unit 111 determines whether or not the current state ofa posture of the mobile communication terminal 1 corresponds to thecontent of the setting (Step S107). That is, if the option “No” for thesetting item “3D display in vertically long state” is enabled, thesetting content corresponds to the case where the screen directiondetermined in Step S101 is “vertically long”. Also, if any of the option“Off” for the setting item “Display in oblique state” or the option “No”for the “3D display in oblique state” is enabled, the setting contentcorresponds to the situation where the screen direction determined inStep S101 is “oblique”.

If the current state of the mobile communication terminal 1 does notcorrespond to the content of the setting that a 3D display is notprovided under a predetermined condition (Step S107: No), the operationmode processing unit 111 notifies the display control unit 114 of this.In this case, the display control unit 114 performs the “3D displayprocessing” (described later in detail) for providing a 3D display (StepS200).

On the other hand, the current state of the mobile communicationterminal 1 corresponds to the content of the setting that a 3D displayis not provided under a predetermined condition (Step S107: Yes), theoperation mode processing unit 111 determines whether or notcorresponding setting items are intended to indicate the display switchto 2D (Step S108). In the example of the operation setting tableillustrated in FIG. 8, this corresponds to when the option “On” for thesetting item “Display in oblique state” is enabled, and the option “No”for the setting item “3D display in oblique state” is enabled.

If the setting items indicate the display switch to 2D (Step S108: Yes),the operation mode processing unit 111 notifies the display control unit114 of this. In this case, the display control unit 114 performs “2Ddisplay processing” (described later in detail) for providing a 2Ddisplay (Step S300).

On the other hand, if the corresponding setting items do not indicatethe display switch to 2D, but indicate “display off” (i.e., the option“Off” for the setting item “Display in oblique state” is enabled) (StepS108: No), the operation mode processing unit 111 notifies the displaycontrol unit 114 of this. In this case, the display control unit 114controls the display unit 160 to stop the display operation, and therebyturns the display off (Step S109).

After the display off processing step, the processing steps in Step S101and subsequent steps are repeated unless a predetermined terminationevent (e.g., power off of the mobile communication terminal 1,transition to the sleep mode, or the like) occurs (Step S110: No).

Also, even in the case where the “3D display processing” (Step S200) or“2D display processing” (Step S300) is performed to thereby perform thedisplay operation, the processing steps in Step S101 and subsequentsteps are repeatedly performed until the predetermined termination eventoccurs (Step S110: No).

Here, the “3D display processing” (Step S200) for providing a 3Ddisplay, and the “2D display processing” (Step S300) for providing a 2Ddisplay are respectively described with reference to flowchartsillustrated in FIGS. 10 and 11. First, details of the “3D displayprocessing” are described with reference to the flowchart illustrated inFIG. 10.

After the processing has been started, the display control unit 114refers to attribute information on image data that is acquired by theimage acquiring unit 112 and a display target, and thereby determineswhether or not the image data is generated for 3D display (Step S201).

Note that the image generated for 3D display refers to an image inwhich, as illustrated in FIG. 4D, a line-based displacement is providedsuch that a 3D display on the display unit 160 can be provided. In thiscase, the displacement is based on parallax, and therefore apreliminarily generated 3D image is based on default parallax. If theparallax does not meet the viewing condition at the time when the 3Ddisplay is provided in the mobile communication terminal 1, i.e., thedistance between eyes and visual distance that are the setting items ofthe conditional parameters, the 3D display is difficult to visuallyrecognize even if the 3D display is directly provided.

Accordingly, if the display target image is a 3D image (Step S201: Yes),the display control unit 114 acquires from the 3D image parallaxinformation indicating the default parallax applied upon generation ofthe 3D image (Step S202), and on the basis of the acquired parallaxinformation, generates right and left images as illustrated in FIGS. 4Band 4C (Step S203). In this case, the right and left images aregenerated by converting the 3D image on the basis of the parallaxinformation.

On the other hand, if the display target image is not a 3D image (StepS201: No), the display control unit 114 applies predetermined parallax(e.g., parallax based on a default distance between eyes and a defaultvisual distance in the conditional parameters) to the acquired image(hereinafter referred to as a “2D image”) to generate right and leftimages as illustrated in FIGS. 4B and 4C (Step S203).

After the right and left images have been generated, the display controlunit 114 refers to the “parameter table” in the storage unit 140 toacquire default values of the conditional parameters for the determinedscreen direction (Step S204). Note that if this 3D display is beingshown for the first time in the mobile communication terminal 1,preliminarily provided default values are acquired, whereas if it is notthe first time, conditional parameters used upon previous 3D display areacquired as the default values.

Note that if the present processing is started by the change in screendirection (i.e., if the determination in Step S103 of the “displaycontrol processing” (FIG. 9) is “Yes”), the conditional parametersemployed before the change in screen direction are acquired as thedefault values. That is, if the screen direction is changed in themiddle of the 3D display, the user can be regarded as the same user, andin this case, the distance between eyes is not changed. Besides, thevisual distance and also the viewing angle can also be made the same.Accordingly, the conditional parameters before the change in screendirection can be directly applied.

After the conditional parameters have been acquired, the display controlunit 114 acquires control parameters related to the acquired conditionalparameters (Step S205). That is, control values of the display panel160A for providing a 3D image display corresponding to the defaultvalues of the conditional parameters for the current screen direction,and control values of the parallax barrier panel 160B for making abarrier pattern preferable for the case are acquired.

Then, the display control unit 114 uses the acquired control parametersto control the display panel 160A. Based on this, the 3D image (see FIG.4D) in which the right and left images generated in Step S203 arerespectively arrayed is displayed on the display panel 160A (Step S206).

Also, by using the acquired control parameters to control the parallaxbarrier panel 160B, the barrier pattern by which the 3D image displayedon the display panel 160A is appropriately visually recognized can beformed on the parallax barrier panel 160B in the determined screendirection (Step S207).

Note that the employed conditional parameters correspond to thedetermined screen direction, but may not be suited to the currentviewing environment because of the use of the default values. If thedefault values are suited to the current viewing environment, the3D-displayed image is appropriately visually recognized, but if not, theimage is not appropriately visually recognized as a 3D image.

For this reason, the display control unit 114 displays on the displayunit 160 a screen that asks the viewer (i.e., user of the mobilecommunication terminal 1) whether or not the current 3D display isappropriately visually recognized (display quality) (Step S208).

The viewer operates the operation unit 150 to input whether or not thecurrent display quality is acceptable. If the input indicating that thedisplay quality is not acceptable is provided (Step S209: Yes), thedisplay control unit 114 changes the conditional parameters (Step S210)to provide a 3D display using control parameters corresponding to thechanged conditional parameters (Steps S205 to S207).

Then, the display control unit 114 displays on the display unit 160 ascreen asking the viewer whether or not the 3D display based on thechanged conditional parameters is acceptable (Step S208), and if it isnot acceptable (Step S209: Yes), further changes the conditionalparameters (Step S210).

The change in conditional parameters in Step S210 is made by, e.g.changing combinations of visual distance and default distance betweeneyes, and then if the 3D display is still unacceptable, a similarcombination change is sequentially made with respect to the otherdistance between eyes.

On the other hand, if the input indicating that the display quality ofthe 3D display is acceptable is provided (Step S209: No), and theacceptable display quality is achieved in the conditional parametersdifferent from the default conditional parameters (Step S211; Yes), thedisplay control unit 114 records the combination of the changedconditional parameters as default (Step S212), and the current flowreturns to the flow of the “display control processing” (FIG. 9).

In addition, if the display quality of the 3D display based on thedefault values acquired in Step S204 is acceptable, and the change inconditional parameters is not made (Step S211: No), the current flowreturns to the flow of the “display control processing” (FIG. 9) withoutupdating the default values.

Next, the “2D display processing” (Step S300) that is performed when a3D display is not provided is described with reference to the flowchartillustrated in FIG. 11.

After the processing has been started, the display control unit 114refers to attribute information on image data that is acquired by theimage acquiring unit 112 and a display target, and thereby determineswhether or not the display target image is a 3D image (Step S301).

If the display target image is a 3D image (Step S301: Yes), the displaycontrol unit 114 further determines whether or not the presentprocessing has been started because of not being in the 3D display mode(hereinafter referred to as a “2D display mode”) (Step S302). That is,the display control unit 114 determines whether or not the presentprocessing has been started because the determination in Step S105 ofthe “display control processing” (FIG. 9) is “No”.

If the display target image is a 3D image, and the display mode is a 2Ddisplay mode (Step S302: Yes), the display control unit 114 displays onthe display unit 160 a screen that asks the viewer (user of the mobileinformation terminal 1) whether or not the display mode is changed to a3D display mode because the display target image is a 3D image (StepS303).

The viewer operates the operation unit 150 to provide input indicatingwhether or not to make the change to the 3D display mode. If the inputindicating the change to the 3D display mode is provided (Step S304:Yes), the display control unit 114 accesses the operation setting tablein the storage unit 140 to change the setting of the display mode fromthe 2D display mode to the 3D display mode (Step S305), and the currentflow returns to the flow of the “display control processing” illustratedin FIG. 9.

In this case, unless the termination event occurs (Step S110: No), theprocessing steps in Step S101 and subsequent steps are again performed,so that in Step S105, the display mode is determined as a “3D displaymode” (Step S105: Yes), and therefore the related 3D display processingis performed.

On the other hand, if the display target image is a 3D image (Step S301:Yes), and the start of the present processing meets the condition formaking the switch to a 2D display in the 3D display mode (i.e., thedetermination in Step S108 of FIG. 9 is “Yes”) (Step S302: No), thedisplay control unit 114 acquires parallax information of the displaytarget 3D image (Step S306) to thereby generate right and left images asillustrated in FIGS. 4B and 4C.

In this case, because of the operation for making the switch to a 2Ddisplay in the middle of the 3D display in the 3D display mode, the 3Dimage generated for 3D display is converted into the respective rightand left images as illustrated in FIGS. 4B and 4C, and one image inwhich interpolation between the right and left images is performed isgenerated and set as a display image (2D image) (Step S307).

In this case, the display control unit 114 controls the parallax barrierpanel 160B to make the barrier pattern transparent (Step S308). That is,the parallax barrier panel 160B is brought into a state where the lightshielding pattern as illustrated in FIG. 5A is absent.

Then, the display control unit 114 controls the display unit 160 todisplay the 2D image generated in Step S307 on the display panel 160A(Step S309), and the current flow returns to the flow of the “displaycontrol processing” (FIG. 9). In this case, the barrier pattern on theparallax barrier panel 160B is made transparent, and therefore the 2Dimage displayed on the display panel 160A is directly visuallyrecognized.

Also, in the case where the display target image is a 3D image (StepS301: Yes), and the display mode is a 2D display mode (Step S302: Yes),if the input made as a response to the screen displayed in Step S303 isnot one asking for the change to a 3D display mode (Step S304: No), a 2Dimage is generated from the right and left images on the basis of theparallax information on the 3D image; the barrier pattern on theparallax barrier panel 160B is made transparent; and then the 2D imageis displayed on the display panel 160A (Steps S306 to S309).

On the other hand, if the display target image is not a 3D image (2Dimage) (Step S301: No), it is not necessary to generate the right andleft images based on the parallax information, and therefore the displaycontrol unit 114 makes the barrier pattern transparent, and thendisplays the 2D image on the display panel 160A (Steps S308 and S309).

Returning to the flow of the “display control processing” (FIG. 9)through such a “2D display processing”, the processing steps in StepS101 and subsequent steps are repeatedly performed until thepredetermined termination event occurs (Step S110: No). Note that if thedetermination of the screen direction in Step S101 is made not at thedisplay start time but in the middle of the display operation (StepS102: No), the screen direction determination unit 113 determineswhether or not any change in screen direction is made (Step S103).

In this case, only if the change in screen direction is made (Step S103:Yes), the processing steps in Step S104 and subsequent steps areperformed, and the display control processing corresponding to thescreen direction at the time is performed. That is, if there is nochange in screen direction, the above-described display control is notperformed (Step S103: No).

Then, along with the occurrence of the predetermined termination event,the “display control processing” is terminated.

Based on the performance of the above-described processing, even if thechange in screen direction of the display unit 160 is made by changingthe posture (direction) of the mobile communication terminal 1 (casing11), the display control corresponding to the screen direction at thetime is performed, and therefore the 3D display is appropriatelyvisually recognized.

Second Embodiment

In the above-described first embodiment, there is exemplified a casewhere the electronic device according to the present invention isimplemented by the straight or slide type mobile communication terminal1 as illustrated in FIGS. 1A to 1C; however, the electronic deviceaccording to the present invention can also be implemented by a mobilecommunication terminal having another configuration.

For example, the electronic device according to the present inventionmay be implemented by, for example, a so-called swing type mobilecommunication terminal 2 as illustrated in FIG. 12.

In this case, the swing type mobile communication terminal 2 has: asillustrated in FIG. 12, a casing 11 held by a user; and a casing 12 thatcan be opened/closed with respect to the casing 11, and is structuredsuch that the display unit 160 is configured to rotate in the casing 12.That is, the screen direction of the display unit 160 can be changedwithout changing a posture (direction) of the casing 11.

Regarding such a swing type mobile communication terminal 2, there aretwo types, for example, one as illustrated in FIGS. 12A and 12B in whichthe display unit 160 rotates using the center of the display unit 160 asa rotary shaft (so-called cycloid type, herein after referred to as a“mobile communication terminal 2A”), and the other one as illustrated inFIGS. 12C to 12E in which the rotary shaft of the display unit 160 isoffset from the center of the display unit 160 thereof (hereinafterreferred to as a “mobile communication terminal 2B”).

In the case of the mobile communication terminal 2A, conditionalparameters, such as viewing distance and distance between eyes do notvary regardless of whether the rotational direction of the display unit160 is right or left. Therefore, it is only necessary to prepare one setof conditional parameters used when the screen direction is horizontallylong.

On the other hand, the mobile communication terminal 2B in which therotary shaft of the display unit 160 is offset as illustrated in FIGS.12C to 12E does not have the same positional relationship as that of thedisplay unit 160 with respect to the user between the case where thedisplay unit 160 is rotated rightward to be brought into a horizontallylong state and the case where the display unit 160 is rotated leftwardto be brought into a horizontally long state. Accordingly, in the caseof the mobile communication terminal 2B having such a type of casingstructure, for example, as illustrated in FIG. 16, two sets ofconditional parameters for the horizontally long state are desirablyprepared for the right rotation and the left rotation, respectively.

That is, the screen directions of the mobile communication terminal 2Bin states illustrated in FIG. 12D and FIG. 12E, respectively, are thesame “horizontally long” in direction; however, one is in a staterotated by 180° with respect to the other one. Therefore to align imagesin the same display direction, one image is horizontally and verticallyinverted after the rotation. In this case, the screen directions are“horizontally long”, and therefore a barrier pattern on the parallaxbarrier panel 160B may be a stripe pattern in the same direction;however, the display image is inverted, and therefore unlesstransmission columns and light shielding columns are swapped inposition, a so-called “reverse view (phenomenon in which images for leftand right eyes are viewed in reverse to each other)” occurs.

Accordingly, in the mobile communication terminal 2B in which the rotaryshaft of the display unit 160 is offset as illustrated in FIGS. 12C to12E, if the screen direction is a horizontally long direction, thecontrol parameters should be prepared for each of the rotationaldirections. The occurrence of the reverse view can be easily preventedonly by using prepared parameters in the display control.

Note that if calculation using control parameters set for one of therotational directions enables control parameters for the otherrotational direction to be obtained, only the control parameters for theone of the rotational directions may be stored in the parameter table inthe storage unit 140. This enables a usage of a storage area in thestorage unit 140 to be reduced.

For example, in the example illustrated in FIGS. 12C to 12E, if theoffset of the rotary shaft of the display unit 160 in FIGS. 12D and 12Eis assumed to be ignorable, or if the transition from the screen in FIG.12A to that in FIG. 12B is allowed for both of the left and rightrotations, control can be performed so as to share one set ofconditional parameters in the case of the horizontally long screendirection without separately storing the conditional parameters for eachof the rotational directions. Only by using determination results forthe cases of the left and right rotations to control (replace) thecontrol parameters such that, for example, the relationship between thetransparent columns and the light shielding columns regarding thebarrier pattern is reversed, the occurrence of reverse view can beeasily prevented, and thereby a 3D display image can be appropriatelyvisually recognized.

Also, if all of the control parameters are adapted and represented by afunction using the conditional parameters as the variable, so thatvalues of the control parameters can be obtained from the function everytime values of the conditional parameters are obtained, informationstored in the parameter table in the storage unit 140 can be limited tothe conditional parameters as illustrated in FIG. 17. This enables theusage of the storage area in the storage unit 140 to be further reduced.

Also, as the mobile communication terminal 2 in which the screendirection of the display unit 160 is not linked to the posture(direction) of the casing 11 held by the user, a mobile communicationterminal (hereinafter referred to as a “mobile communication terminal2C”) having a casing that opens/closes in two directions as illustratedin FIGS. 13A to 13C, or the like can also be applied with the presentinvention.

Even in such a mobile communication terminal 2, by performing theprocessing exemplified in the above-described first embodiment, displaycontrol depending on the screen direction of the display unit 160 isperformed, and a 3D display image is thereby appropriately visuallyrecognized.

This case is partially different in a configuration for determining thescreen direction of the display unit 160 from the mobile communicationterminal 1 exemplified in the first embodiment. That is, as illustratedin FIG. 14, a style detecting unit 180 is configured in place of thegravitational direction detecting unit 170 in the first embodiment.

The gravitational direction detecting unit 170 is a part that detects agravitational direction acting on the mobile communication terminal 1;however, the style detecting unit 180 according to the presentembodiment is configured to detect a style of the display unit 160 thatvaries according to the opening/closing or rotation of the casing. Thestyle detecting unit 180 of the mobile communication terminal 2A or 2Bincludes a sensor that detects the rotational direction and rotationalangle of the display unit 160, and the like, whereas the style detectingunit 180 of the mobile communication terminal 2C includes a sensor thatdetects an opening/closing direction and opening/closing angle of thecasing 12, and the like.

In the case of the present embodiment, the functional configurationachieved by a control unit 110 is the same as that in the case of thefirst embodiment; however, as illustrated in FIG. 15, a screen directiondetermination unit 113 determines, on the basis of a result of thedetection by the style detecting unit 180, the screen direction of thedisplay unit 160. In this case, the screen direction determination unit113 achieved by the control unit 110 of the mobile communicationterminal 2B as illustrated in FIGS. 12C to 12E determines not onlywhether the screen direction of the display unit 160 is a verticallylong or horizontally long direction, but also the rotational directionof the display unit 160.

In the mobile communication terminal 2 having such a configuration, byperforming the “display control processing” exemplified in theabove-described first embodiment, the display control depending on thescreen direction of the display unit 160 is performed, and even when thedisplay unit 160 is rotated, or the opening/closing direction of thecasing is changed, a 3D display image is appropriately visuallyrecognized.

As described above, by applying the present invention as in theabove-described embodiments, a 3D display can be appropriately visuallyrecognized in an electronic device in which the screen direction ischanged, such as a mobile communication terminal or the like.

The present embodiment can determine the screen direction on the basisof the detection of the gravitational direction acting on the mobilecommunication terminal, or the detection of the style of the mobilecommunication terminal, and can therefore be applied to mobilecommunication terminals having various configurations.

Also, by using the conditional parameters and control parameters toperform display control, the display control for providing an optimum 3Ddisplay can be instantly performed.

Further, the user is asked whether or not the 3D display is acceptable,and on the basis of the response to this, the parameters are changed, sothat the display can be improved.

Still further, display control leading to an acceptable display statecan be performed in a short time by using changed parameters orpreviously used parameters.

Yet further, the parallax barrier is controlled to thereby performdisplay control, and therefore the display control leading to anacceptable 3D display can be performed.

Yet still further, by performing display control so as to prevent a 3Ddisplay, a 2D display is separately used from the 3D display to be ableto achieve a display easily viewable to the user.

Also, in the case of a vertically long display having a relatively small3D display visual effect, by performing display control to prevent a 3Ddisplay, a display putting more emphasis on ease of viewing than thevisual effect can be provided.

On the other hand, in the case of a horizontally long display in whichthe visual effect based on a 3D display can be expected, by performingdisplay control to provide a 3D display, the display putting emphasis onthe visual effect can be provided.

Also, by performing display control to prevent a 3D display when thescreen direction is oblique, an easily viewable display can be providedeven in a condition in which a 3D display is difficult to visuallyrecognize.

In this case, besides the switch to a 2D display, display control tostop a display operation can also be performed, and therefore a displayaccording to a user's intention can be provided.

Also, display control is performed depending on whether the attribute ofa display target image is for 3D or 2D, and therefore a more appropriatedisplay can be provided.

The above-described embodiments are examples, and an applicable scope ofthe present invention is not limited to any of the embodiments. That is,various applications are possible, and any embodiment can be included inthe scope of the present invention.

For example, the above-described embodiment exemplifies the case wherethe electronic device according to the present invention is embodied bythe mobile communication terminal; however, the present invention can beapplied to various electronic devices without limitation to the mobilecommunication terminal if there is provided a display unit that makesthe image stereoscopically visually recognizable.

Also, there is exemplified the case where each of the display panel andbarrier pattern is embodied by a liquid crystal display panel; however,the present invention can be applied, without limitation to the liquidcrystal, with another device if the device can implement each of thedisplay and the barrier, for example, even if the display panel is aself light emitting display device such as an organic EL or plasmadisplay device.

Also, the mobile communication terminal 1 or 2 may be configured asillustrated in FIG. 18. A detecting unit 190 in FIG. 18 is implementedby, for example, an imaging device (camera) that can image the face ofthe user (viewer), image recognition processing unit that can recognizea face, distance sensor, or the like. The detecting unit 190 may beadapted such that it detects distance between eyes from an imaged image,visual distance from the distance sensor, or the like, and on the basisof this, parameters are automatically set.

Further, not only an electronic device preliminarily provided with theconfiguration according to the present invention but an existingelectronic device can be made to function as an electronic deviceaccording to the present invention by applying a program to the existingelectronic device.

The method for applying such a program is arbitrary, and for example,the program can be applied and stored in a storage medium such as aCD-ROM or memory card, and besides, for example, also applied through acommunication medium such as the Internet.

Having described and illustrated the principles of this application byreference to one or more preferred embodiments, it should be apparentthat the preferred embodiments may be modified in arrangement and detailwithout departing from the principles disclosed herein and that it isintended that the application be construed as including all suchmodifications and variations insofar as they come within the spirit andscope of the subject matter disclosed herein.

What is claimed is:
 1. An electronic device comprising a display unitthat can provide a three-dimensional display making an imagestereoscopically viewable, characterized in that the electronic devicecomprises: a determination unit that determines at least a screendirection of the display unit; a parameter acquiring unit that acquiresat least a conditional parameter associated with a visual recognition ofthe three-dimensional display, and a control parameter associated withan operation control for the display unit, the conditional parameterbeing tied to the screen direction, the control parameter being tied tothe conditional parameter; and a display control unit that performs aswitch control associated with the three-dimensional display on a basisof the conditional parameter that is tied to a result determined by thedetermination unit and the control parameter that is tied to theconditional parameter, wherein at a first-time start of thethree-dimensional display, the display control unit performs the switchcontrol using a predetermined default value of the conditionalparameter, and wherein at a start of the three-dimensional displayexcept for the first-time start of the three-dimensional display, thedisplay control unit performs the switch control using a conditionalparameter used in a previous three-dimensional display, or, if a changein the screen direction of the display unit occurs during thethree-dimensional display, the display control unit performs the switchcontrol in accordance with a changed screen direction of the displayunit using the conditional parameter that is used before the changeoccurred in the screen direction of the display unit.
 2. The electronicdevice according to claim 1, wherein the determination unit furthercomprises an image determination unit that determines whether or not animage to be displayed on the display unit has been created for thethree-dimensional display, and wherein the display control unit switchesto determine whether to provide the three-dimensional display on a basisof a result determined by the image determination unit.
 3. Theelectronic device according to claim 1, further comprising: an inquiryunit that asks a user of the electronic device whether thethree-dimensional display is acceptable, wherein the display controlunit changes a condition associated with the visual recognition of thethree-dimensional display to be used in the switch control, on a basisof an input in response to inquiry by the inquiry unit.
 4. Theelectronic device according to claim 1, further comprising: a parameterstorage unit that preliminarily stores at least the conditionalparameter among parameters acquired by the parameter acquiring unit,wherein the parameter storage unit identifiably stores a conditionassociated with the visual recognition of the three-dimensional displayused in the switch control.
 5. The electronic device according to claim1, wherein the display control unit switches to determine whether toprovide the three-dimensional display on a basis of a determined screendirection of the display unit.
 6. The electronic device according toclaim 5, wherein the display control unit performs the switch control tonot to provide the three-dimensional display if the determined screendirection of the display unit is a vertically long direction.
 7. Theelectronic device according to claim 5, wherein the display control unitperforms the switch control to provide the three-dimensional display ifthe determined screen direction of the display unit is a horizontallylong direction.
 8. The electronic device according to claim 5, whereinthe display control unit performs the switch control to not to providethe three-dimensional display if the determined screen direction of thedisplay unit is an oblique direction.
 9. The electronic device accordingto claim 1, wherein the display control unit performs the switch controlso as to stop a display operation in accordance with a determined screendirection of the display unit.
 10. A computer-readable non-transitoryrecording medium recording a program that instructs a computer, whichcontrols an electronic device comprising a display unit that can providea three-dimensional display making an image stereoscopically viewable,to realize functions comprising: a determination function fordetermining at least a screen direction of the display unit, a parameteracquiring function for acquiring at least a conditional parameterassociated with a visual recognition of the three-dimensional display,and a control parameter associated with an operation control for thedisplay unit, the conditional parameter being tied to the screendirection, the control parameter being tied to the conditionalparameter; and a display control function for at a first-time start ofthe three-dimensional display, performing a switch control using apredetermined default value of the conditional parameter on a basis ofthe conditional parameter that is tied to a determination result and thecontrol parameter that is tied to the conditional parameter, and at astart of the three-dimensional display except for the first-time startof the three-dimensional display, performing the switch control using aconditional parameter used in a previous three-dimensional display, or,if a change in the screen direction of the display unit occurs duringthe three-dimensional display, performing the switch control inaccordance with a changed screen direction of the display unit using theconditional parameter that is used before the change occurred in thescreen direction of the display unit on a basis of the conditionalparameter that is tied to a determination result and the controlparameter that is tied to the conditional parameter.